Vitellogenin is a large serum phospholipoglycoprotein normally
produced in the liver of female oviparous vertebrates in response to
circulating endogenous estrogen. It is taken up by the ovary as a precursor
of egg yolk proteins. Vitellogenin is normally undetectable in the plasma
of males as they lack circulating estrogen, although its gene can be induced
by estrogen exposure. The present study was carried out on fifty male Nile
tilapia (Oreochromis niloticus). Fish divided into equal five groups(n=10),
control group (Group1) and four treated groups; Group 2 exposed to 10mg
phenol/L, Group 3 exposed to 5ppm potassium permanganate/L, Group 4
and Group 5 exposed to mixture of potassium permanganate 2.5 ppm and
5ppm respectively with phenol 10mg/L. After four weeks of exposure,
tissues and blood samples were taken and the results showed that plasma
testosterone level was decreased in the Group2 treated with phenol while
plasma vitellogenin and vitellogenin gene expression were increased. In
the Group exposed to potassium permanganate only Group3 or exposed to
a mixture of potassium permanganate in addition to phenol Group 4,5
resulted in lowering of plasma vitellogenin and vitellogenin gene
expression also increased of testosterone hormone compared to group2.
The results of the present study reinforce the efficiency of potassium
permanganate as an oxidative agent in the amelioration of the toxic effects
of phenol pollution in aquaculture.